Methods and apparatus for controlling movement of receptacles

ABSTRACT

Methods and apparatus for controlling the movement of portable receptacles within a materials handling facility are described. The materials handling facility utilizes at least one linear induction motor (LIM) to move the portable receptacles having conductive elements from a first location to a second location within the facility. The LIMs may be configured such that most, if not all, of the movement of the receptacles is controlled by the application of energy from the LIMs to the conductive elements of the receptacles. This energy may cause the receptacles to move from one LIM to another LIM, where each LIM in sequence can apply force to the receptacle to pass it to the next LIM in the sequence. In some implementations, the portable receptacles are configured such that at least a base portion of the receptacle includes a conductive element to interact with the LIMs, while maintaining an overall light-weight configuration.

BACKGROUND

Each passing day, more and more consumers utilize the internet topurchase goods. This has resulted in an ever growing use of fulfillmentcenters, distribution centers, warehouses and materials handlingfacilities (collectively, “materials handling facilities”) as the placeswhere the goods are received, stored, prepared for shipment, and evenpotentially shipped (shipment may, for example, occur at a separatefacility). When a consumer orders a specific item, the ordered number ofunits of that item are identified at one or more specific locationswithin the materials handling facility, transferred to another locationwithin the facility for packaging in a shipment container (such as acardboard box), and prepared for shipment to the consumer.

Conventional materials handling facilities typically utilize a series ofconveyor belts which deliver generic totes or receptacles from onespecific location to another within the material handling facility.These conveyor belts are usually operated in an “always on” mode, inwhich they are constantly moving, even if no receptacles are beingmoved. Keeping these conveyors constantly moving can require asignificant allocation of energy, as the conveyor belts themselves areoften very heavy. In addition, such systems are inherently very noisydue to the constant movement of the conveyors, and all of the movingparts can require frequent maintenance and generate large amounts ofdust and dirt, which can reduce the reliability of such systems.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows an illustrative schematic view of a linear inductionmotor-driven materials handling system in accordance with embodiments ofthe present disclosure;

FIG. 2 shows a schematic top view of a linear induction motor-drivenmaterials handling system in accordance with embodiments of the presentdisclosure;

FIG. 3 shows a schematic side view of a linear induction motor-drivenmaterials handling system in accordance with embodiments of the presentdisclosure;

FIG. 4 shows a schematic perspective illustration of the interactionbetween the linear induction motor and the portable receptacle inaccordance with embodiments of the present disclosure;

FIGS. 5A-5D show schematic side views of some alternate ways to mountthe linear induction motor in accordance with embodiments of the presentdisclosure;

FIG. 6 shows a schematic perspective view of a linear inductionmotor-driven materials handling system in accordance with embodiments ofthe present disclosure;

FIG. 7 shows a schematic perspective view of a linear inductionmotor-driven materials handling system in which multiple receptacles aredriven by an individual linear induction motor in accordance withembodiments of the present disclosure;

FIG. 8. shows a schematic top view of a linear induction motor-drivenmaterials handling system in which portable receptacles are moved to anyone of multiple locations in accordance with embodiments of the presentdisclosure;

FIG. 9 shows a schematic side view of a linear induction motor-drivenmaterials handling system in which portable receptacles are transportedthrough various elevations in accordance with embodiments of the presentdisclosure;

FIG. 10A shows a schematic perspective view of a portable receptacleconstructed in accordance with embodiments of the present disclosure;

FIGS. 10B-10G show schematic views of a portion of a portable receptacleconstructed in accordance with embodiments of the present disclosure;

FIGS. 10H-10K show alternate physical configurations of a portablereceptacle that provides a reduced lower surface area in contact with alinear induction motor-driven materials handling system constructed inaccordance with embodiments of the present disclosure;

FIGS. 11A-11B show schematic views of a portable receptacle constructedin accordance with embodiments of the present disclosure;

FIG. 12 is a flow diagram of a method of fulfilling an order utilizing amaterials handling system in accordance with embodiments of the presentdisclosure; and

FIG. 13 is a flow diagram of a method of moving a portable receptacle toits next location in accordance with embodiments of the presentdisclosure.

DETAILED DESCRIPTION

The present disclosure, as set forth below, is directed to variousembodiments of methods and apparatus for transporting portablereceptacles utilizing linear induction motor-driven materials handlingsystems. In some embodiments, linear induction motors (“LIMs”) are usedas a mechanism for transporting individual portable receptacles from afirst location to a second location within the given materials handlingsystem. In other embodiments, a single LIM may be utilized to movemultiple portable receptacles from a first location to a second locationin the system, whereby the LIM causes a first portable receptacle tobegin moving and the electromagnetic force generated by the LIM isstrong enough to move a series of receptacles located adjacent to eachother within the system. In at least some embodiments, the LIMs aresized and configured such that the portable receptacles are at leastpartially levitated to reduce the force needed to drive the receptacleswithin the system by reducing the frictional force between the portablereceptacles and the surface on which they move. In at least some otherembodiments, individual portable receptacles can be moved from any oneof many given starting positions to any one of many given intermediatepositions and/or end positions. At some of those intermediate positions,for example, additional items made be added to the receptacle in orderto build the order before it is packaged for shipment. In this manner,for example, a given portable receptacle might be utilized to accumulatemultiple items in a given consumer's order, rather than simply beingutilized to a transport a given item within the system.

In some embodiments, a materials handling system includes one or moreguide tracks to guide the portable receptacles. Each guide track mayinclude a receiving surface that includes one or more LIMs and one ormore side walls capable of guiding the portable receptacles and/or limitthe movement of the portable receptacles such that the portablereceptacles stay within the confines of the materials handling system.In some embodiments, the direction in which a given portable receptacleis traveling may be altered via the intervention of a physical device,such as a guide arm operable via a switch to redirect the receptaclefrom a given path toward point A to a given path toward point B. In atleast some other embodiments, the direction in which a portablereceptacle is moving is altered via one or more LIMs oriented such thatthe one or more LIMs alter the trajectory of the portable receptaclefrom a first path to a second path.

While many embodiments described herein relate to materials handlingsystem and the various ways that such systems utilize LIMs to moveportable receptacles to different locations within a materials handlingsystem, at least some embodiments are directed to the portablereceptacle itself. In many instances, portable receptacles are, by theirnature, light-weight, but sturdy devices that can be used to transportone or more items ranging in weight from very light (e.g., less than 10ounces) to very heavy (e.g., greater than 20 pounds). Accordingly,portable receptacles may be manufactured from one or more non-conductivematerials including, but not limited to, various plastics (e.g.,polyethylene terephthalate (“PET”), polypropylene, polystyrene, etc.),rigid rubber, and/or cardboard, and combinations thereof. Suchnon-conductive materials are capable of providing the necessary rigidityand strength for the portable receptacle while maintaining thelight-weight form factor needed to facilitate movement of the portablereceptacles throughout the materials handling system.

However, while portable receptacles made of such non-conductivematerials are suitable for most materials handling systems operatingusing standard conveyer belts and pulley systems, these receptacles arenot capable of interacting with a materials handling system includingone or more LIMs as mechanisms to move the portable receptacles from onelocation to another within the materials handling system, such that theportable receptacles themselves are part of the driving motor. Forexample, in conventional LIM-based systems, the LIM carriers (i.e., thestator portion of the linear motor) are designed to hold the receptaclessecurely in place while the carriers transport the receptacles about thesystem. In accordance with embodiments described below, the portablereceptacles are modified to include conductive materials such that thereceptacles themselves take the place of conventional LIM carriers andare therefore an integral part of the linear motors that are used tomove the receptacles about the system, which can greatly reduce thenumber of moving parts required in these systems. In some embodiments,portable receptacles may be made solely of conductive materials (e.g.,iron, copper, etc.). However, creating portable receptacles solely outof conductive materials may be costly, and may create receptacles thatare too heavy or cumbersome to move efficiently within the materialshandling system.

In some embodiments, the portable receptacles may be modified orredesigned such that at least a portion of the portable receptacleincludes a conductive element that can interact with the LIMs in thematerials handling system, while the remaining portions of the portablereceptacle include one or more non-conductive materials. Theseconductive materials may be attached to the inner or outer surface ofthe receptacles, or they may be embedded within the non-conductiveportion of the receptacles during the manufacturing of the receptacles.In other embodiments, the material used to manufacture the receptaclesmay be doped with an appropriate amount of conductive material such thatthe receptacles are produced in a manner that they can reliably interactwith the LIMs in the material handling system. For example, the portablereceptacles can, for example, be manufactured with a portion ofconductive material located in a bottom portion of the receptacles, orthe bottom portion of the receptacle can be impregnated with multipleindividual conductive portions, such as conductive strips that may beutilized to assist in transporting and/or changing the direction of agiven receptacle in the system. Alternately, some or all of the portablereceptacles may be formed of a non-conductive material that is dopedwith one or more conductive elements or particles, for example, as partof an injection-molding process (this may be accomplished, for exampleby utilizing the doped material when forming the bottom of thereceptacle and non-doped material when forming the side walls to keepthe receptacles as light and inexpensive as possible).

Embodiments described below include materials handling systems thatutilize one or more LIMs to facilitate movement of portable receptaclesthat are at least partially conductive, such that the receptaclesthemselves form part of the driving inductive motor. In this manner, thematerials handling systems utilize less energy because only the drivingLIMs need to be active, and they generate less noise and dirt due to thesignificant reduction in moving parts in the transport system itself.Further, the reduction in moving parts may reduce the need for frequentor periodic maintenance of such moving parts. In addition, the reducedamount of friction between the portable receptacle and guide trackallows for the portable receptacles to travel substantially unimpededand with great efficiency. In some embodiments, the electromagneticforces between the LIMs and the conductive elements of the portablereceptacles enable the portable receptacles to levitate above the guidetrack, thereby substantially removing any frictional forces. Anotherbeneficial aspect of such materials handling systems is that the amountof energy needed to operate the one or more LIMs is much less than for atypical conveyance system as only enough energy is needed to “push” onereceptacle from one LIM to a next LIM. A further advantage of suchmaterials handling systems is that the systems are substantiallydeterministic, such that the position of each portable receptacle shouldbe capable of being calculated beforehand, regardless of the weight ofthe receptacle or of any item placed therein.

FIG. 1 shows an illustrative schematic view of material handling system100, which includes receiving surface 102, linear induction motors(“LIMs”) 106, one or more sensors 112, a network 114, a data store 116,and a control module 120. System 100 may also include one or more userdevices 118 that can be used to access, monitor and/or control variousaspects of system 100. Sensors 112 may include any number and variety ofdifferent sensors, depending on the application. For example, sensors112 may, in some embodiments, be used to monitor the location and/orcontents of receptacle 110 as it travels about materials handling system100, and this could be accomplished in a number of different ways, suchas through the use of RFID tags attached to receptacle 110 or itemscontained therein, in which case sensors 112 would be RFID readers.Alternately, an identifier, e.g., a sticker, could be placed on eachreceptacle 110 or item contained therein that can include a QR or barcode, in which case sensors 112 would be a corresponding scanner/reader.Other embodiments can include imaging sensors, thermal sensors,photographic imaging devices, etc. Still other embodiments may includesensors that can measure the weight of receptacle 110, which could beused to verify that certain selected items have been placed therein (inwhich case the individual weight of such items would be known).

As indicated above, system 100 may also include one or more user devices118 that can be used by employees working with system 100 to fulfillcustomer orders. In some embodiments, user devices 118 could be any oneof a number of smartphones, running a dedicated “app” that couldinterface with system 100 via a Bluetooth or WiFi connection (throughcommunications module 128 in control module 120). Alternatively, userdevices 118 could be tablet computers that could also be configured torun a dedicated app and be connected to system 100 via a Bluetooth orWiFi connection. In addition, user devices 118 could instead bededicated hand held devices that are designed specifically to be usedwith system 100 to enable a user, for example, to monitor the status: ofsystem 100, of individual receptacles 110, and/or of individual customerorders, etc. In some embodiments, for example, user devices 118 could beutilized by employees working at individual workstations (see, forexample, the description below related to workstation 160) at whichreceptacles 110 stop in order to be filled with one or more items. Theemployee could utilize user device 118 to inform system 100 when thedesignated task for that individual workstation has been completed sothat system 100 could continue transporting a given receptacle 110through the remainder of its path until all of the items designated forthat given receptacle have been loaded therein and the given receptaclehas been moved to the appropriate location for packaging and shipping ofthose items.

While system 100 may be configured to include hard-wiredinterconnections between individual electronic components, such as LIMs106 and control module 120, more benefits may be obtained when network114 is utilized for electronic communications, such as is illustrated inFIG. 1, where each LIM 106, sensor 112, data store 116, user device 118,and control module 120 are all coupled together via network 114. Theconnections to network 114 may be physical, such as via an Ethernetconnection, or they may be wireless, such as via a Bluetooth and evencellular connection (and system 100 may include any combination of suchconnections, as appropriate). Materials handling system 100 isconfigured to transport portable receptacles 110 from at least onelocation to at least one other location through the application ofelectromagnetic forces that are established between LIMs 106 and aconductive portion of receptacles 110, such that the receptacles formpart of the driving induction motor. In particular, LIMs 106, as brieflydescribed above and shown in the figures, are essentially just a portionof the actual linear induction motor, while the conductive portion ofreceptacles 110 form the remaining portion of the linear inductionmotor. As is described in more detail below, the LIM 106 is used tocreate the magnetic field that interacts with the conductive portion ofreceptacles 110.

Control module 120 may include a variety of different modules, such asprocessor(s) 122, memory 124 (such as conventional random access memory“RAM”), data storage 126 (which may include storage such as hard drives,FLASH drives and the like), communications circuitry 128 (such as, forexample, Ethernet, Bluetooth and cellular interface circuitry), sensorreceiver modules 132 (which may include circuitry to monitor signalsfrom one or more of sensors 112), and signal generation module 134(which may, for example, include circuitry to generate signals to driveand control LIMs 106, such as pulse width modulation signals as will bedescribed in more detail below).

Processor(s) 122 may include, for example, one or more individualmicroprocessors which can be configured to work independently or inconjunction with each other (such as in a distributed processingsystem), and the individual processors may be single-core or multi-coreconfigurations. Processor(s) 122 can be coupled within control module120 to each of memory 124 (which itself may include random access memoryor “RAM”, read only memory or “ROM,” etc., which is used to storevarious portions of information for use by processor(s) 122), storage126 (which may include conventional hard drives, FLASH memory devices,hybrid devices, cloud storage, etc., that can all be used to storeprograms, applications, data, etc. for use by processor(s) 122),communications module 128, sensor module 132 and signal generationmodule 134. Communications module 128 can include, for example, thenecessary interface to control incoming and outgoing communicationsthrough Bluetooth devices, Wi-Fi connections, cellular phone serviceconnections, etc., as well as providing the basic interface for Ethernetcommunications that can be used to connect control module 120 to network114. Sensor module 132 can provide, for example, control signals thatmay be used to activate and monitor sensors 112 throughout system 100,and it may also be utilized to receive sensed signals and provide thereceived signals to processor(s) 122 such that processor(s) 122 mayanalyze the received signals and generate an accurate representation ofthe status of system 100. Signal generation module 134 may be coupled toprocessor(s) 122 such that processor(s) 122 can instruct signalgeneration module 134 what type of driving signals to generate for aspecific LIM, and to provide the activation signals to signal generationmodule 134 that can cause the generated driving signals to be providedto a specific LIM 106.

System 100 also may include data store 116 that can be utilized for avariety of purposes, such as to store the status and location ofindividual customer orders, to send inventory requests to control module120 that may then initiate the instructions to fulfill consumer orders,to store inventory control information such as bar codes for individualitems, to store information regarding each individual portablereceptacle in system 100, and other information as may be appropriate.Additional information that may be included in data store 116 caninclude properties or characteristics, such as approximate weights, ofitems that may be deposited within receptacles 110, individualinformation concerning LIMs 106, such as LIM identifiers and LIMlocations, as well as the locations and processing capabilities ofworkstations within system 100.

Receiving surface 102 may be formed from a variety of materials. Forexample, surface 102 may be formed from aluminum (which may or may notbe polished), stainless steel, or any number of other metals orplastics. Any of these materials may be selected in order to attempt tolower the surface friction between surface 102 and the portion ofreceptacle 110 that makes contact with surface 102 (various differentconfigurations of receptacle 110 are described below, which personsskilled in the art will appreciate are intended to be illustrative andnot limiting). In addition, these materials may be coated with anynumber of substances in order to further reduce the surface friction,such as a coating of Teflon or silicon-based material. In otherembodiments, surface 102 may include a number of small holes that couldbe formed from drill or laser, through which compressed air may beapplied to cause receptacles 110 to float through system 100 (usingprinciples that are similar to those used in designing an air hockeytable). In general, the lower the surface friction, the less forcerequired to be generated by LIMs 106 in order to propel receptacles 106along (and therefore, less energy is required to keep system 100running).

Surface 102 may also, for example, be formed of non-continuousmaterials, such as a series of rollers which rotate in a highlyefficient manner through the use of internal ball bearings. Moreover,surface 102 may be a wide-open, free-form surface, such that receptaclescould be propelled in any direction based on the configuration of LIMs106, or surface 102 may be combined with rails 104 (see FIG. 2 describedbelow) to provide a higher degree of reliability that receptacles willtravel along their intended path. The use of rails 104, however, maylimit the different paths that receptacles 110 can be propelled (forexample, as described in more detail below with respect to FIG. 8, ifrails 104 are not utilized, receptacles 110 can be propelled along adirection Q such that the receptacles 110 cross path X). Moreover, whilethe figures show surface 102 as generally a solid surface, surface 102may instead be formed as a pair of rails or individual surfaces on whichthe outer edges of receptacles 110 would travel (the rails, for example,could be formed from PVC tubes or other similar implementations). Inthat case, LIMs 106 could be mounted on individual, free-standingcolumns located in between the two portions that make up surface 102,such that there would be no surfaces, components or structures betweenLIM 106 and receptacle 110 as receptacle 110 passes over LIM 106. Inthese instances, the surface friction between surface 102 and receptacle110 would be reduced simply because there would be fewer points ofcontact between them.

FIG. 2 shows a schematic top view of a portion of materials handlingsystem 100. As shown in FIG. 2, materials handling system 100 mayinclude a receiving surface 102, one or more guides 104 and one or moreLIMs 106 that are used to control the movement of portable receptacles110 through system 100 from a first position to a second position, andsubsequently to a third position, fourth position, and/or nth positionas needed. For example, at a first position, a portable receptacle mayreceive a first item, and then be moved to a second position where thereceptacle may receive a second item and/or have the first item removed.

Receiving surface 102 may correspond to a surface upon which the one ormore portable receptacles 110 move (or, as described above, surface 102may be implemented as a pair of rails or individual surfaces with LIMs106 located between them). The various LIMs are operable to be locatedon receiving surface 102, embedded within receiving surface 102,positioned below receiving surface 102 (see, for example, FIGS. 5A-5Cand the corresponding description below), and/or located betweenportions of surface 102. As described above, in some embodiments,receiving surface 102 is operable to reduce the surface friction betweenthe one or more portable receptacles moving thereon, such as through theuse of a coating of silicon-based material, to reduce surface friction(other materials, for example, may be similarly utilized to minimize thesurface friction between receptacles 110 and surface 102). Various othermechanisms to reduce the amount of surface friction between receivingsurface 102 and portable receptacles 110 may also include modifying thetemperature of receiving surface 102. Persons of ordinary skill in theart will recognize that any other suitable technique may be used tolower the surface friction between receiving surface 102 and portablereceptacles 110, and the aforementioned are merely exemplary.

Receiving surface 102, in some embodiments, can be substantially planarand continuous, however, other configurations are also disclosed herein.For example, receiving surface 102 may be wider at one position andthinner at another position (see, for example, FIG. 2). Further,receiving surface 102 may include one or more rails or tracks (forexample, similar to train tracks), instead of a continuous, planarsurface, upon which the receptacles 110 can move between locations ofthe system 100. Receiving surface 102 may also be curved, both in thedirection of motion of portable receptacles 110 and/or perpendicular tothe direction of motion. For example, a center portion of receivingsurface 102 may be raised in relation to a side portion of receivingsurface 102. Receiving surface 102 may also be oriented at any suitableangle with respect to gravity such that portable receptacles 110 arecapable of being moved from a first height to a second height due togravitational forces.

In some embodiments, materials handling system 100 may include one ormore guides 104 that operate to keep receptacles 110 on receivingsurface 102 while in motion. This may be especially useful in situationswhere malfunction of one or more LIMs can occur and portable receptacles110 are unconstrained—protecting them from potentially falling off anedge of surface 102. Guides 104 may be short rails along the sides ofsurface 102 (see, for example, FIG. 6), or guides 104 may be completeside-sections of material (similar to the material that forms surface102), such that there is virtually little chance of any of receptacles110 falling off of surface 102 regardless of the circumstances. Itshould be noted that it may also be possible to design system 100 suchthat the interaction between LIMs 106 and receptacles 110 is so tightlycoupled or controlled that guides 104 may not be necessary when thesystem is provided with electricity. For example, LIMs 106 may belocated close together along a direction of movement of the receptacles110 on the receiving surface 102, such that a moving receptacle 110moves directly from one LIM 106 to another, with little to no freemovement.

Accordingly, guides 104 may be designed in any suitable manner,depending on the application. For example, guides 104 may vary in heightor shape along a length of receiving surface 104, such that they may bestraight, curved or any combination thereof. For example, guides 104 maybe at a first height at a first section of receiving surface 102 whichmay be straight, and at a second height at a second section of receivingsurface 102, which itself may be curved. Thus, guides 104 may besubstantially flat, curved, or any combination thereof.

In other embodiments, fewer LIMs may be utilized along a given portionof surface 102, such as through the use of only LIMs 108 and 109 asshown in FIG. 2 (LIMs 106, 108, and 109 may be substantially identicalto each other). As shown in FIG. 2, LIMs 108 and 109 are spacedrelatively farther apart from each other than any two adjacent LIMs 106of the four LIMs 106. Alternatively, LIMs 106 (and/or LIMs 108, 109),may actually be installed in system 100, and any suitable operation mayutilize each of LIMs 106 together or separately. For example, oneparticular operation may utilize only LIMs 108 and 109, other operationsmay utilize LIMs 106 and 108, and still other operations may utilize anycombination of installed LIMs, such as LIMs 106, 108 and 109. In oneembodiment, for example, when only LIMs 108 and 109 are utilized, theforce applied to receptacles 110 may be such that a given receptacle 110moves freely, or substantially freely, from LIM 108 to LIM 109. Undersuch circumstances, a given receptacle 110 may be provided enoughpropulsion from the force applied by LIM 108 to reach LIM 109, at whichpoint LIM 109 may be capable of providing an additional force toreceptacle 110 causing the receptacle to move to another position withinmaterials handling system 100.

In some embodiments, a first LIM, such as LIM 108, may be capable ofproviding enough force to move multiple portable receptacles 110. Forexample, a first portable receptacle 110A, a second portable receptacle110B and a third portable receptacle 110C may be positioned adjacent toone another on receiving surface 102 between two LIMs, such as LIMs 106Aand 106C (see FIG. 7). A force applied to third portable receptacle 110Cby LIM 106C is operable to move all three receptacles 110A, 110B, and110C along receiving surface 102 toward LIM 106A, eitherelectromagnetically or through a mechanical momentum transfer (e.g.,elastic/inelastic collision). In this particular embodiment, multiplereceptacles 110 are capable of being “pushed” along receiving surface102 by a single LIM (e.g., LIM 106C), thereby further decreasing theamount of energy needed to operate materials handling system 100.

Materials handling system 100 as shown in FIG. 2 may be a partialrepresentation of an actual materials handling system that may beutilized to move items selected and ordered by a consumer from one ormore given storage locations to one or more packing locations in orderto prepare the ordered items for shipment to the consumer. In addition,materials handling system 100 may also be utilized to move the packeditems located in the shipment boxes to one or more additional locationsfrom which shipments may depart the materials handling system 100.

FIG. 3 shows a schematic side view of materials handling system 100which, as described above, includes receiving surface 102 and LIMs 106.As shown in FIG. 3, system 100 also includes lower surface 115 which maybe located below receiving surface 102 by a given distance H. Distance Hshould be set such that LIMs 106 are close enough to surface 102 suchthat they will be able to interact with the conductive elements ofreceptacles 110 moving across surface 102. Lower surface 115 may beutilized for a variety of different reasons. In some embodiments, lowersurface 115 may be implemented as a series of sliding drawers thatprovide easy access to LIMs 106 for maintenance and repair. Alternately,lower surface 115 might be implemented as a single sheet of materialthat is pre-populated with LIMs to simplify the fabrication process ofsystem 100. LIMs 106 may be installed in various other manners, such asthose described below and shown in FIGS. 5A-5D. As shown in FIG. 3, LIMs106 may be located a common distance D apart from each other, or system100 may be configured such that some LIMs 106 may be located a distanceD apart from each other while others are either closer together orfarther apart from each other depending on the desired results. Forexample, if surface 102 was configured as an incline, LIMs 106 may belocated closer together so that the driving force from LIMs 106 ismaintained as receptacles 110 move up the incline (see, for example,FIG. 9).

FIG. 4 is a three dimensional illustration that shows the basicprinciples that are utilized in accordance with embodiments of thedisclosure herein. In at least one embodiment, each of LIMs 106 iscontrolled by control module 120, which is capable of sending one ormore control signals (generated by signal generator 134) to any LIMwithin system 100. Those signals may include simple alternating currents(i.e., AC), or they may include more complicated signals, such aspulse-width modulated (“PWM”) signals that can be used to provide morepower to the LIMs in a more precisely controlled manner. Through theprecise application of these signals, control module 120 is operable tokeep receptacles 110 moving through materials handling system 100 in anorderly fashion in compliance with the operations of the materialshandling system 100 (e.g., the ability to stop one or more receptacles110, change the direction of motion of receptacles 110, etc.). Whilecontrol module 120 is only shown being connected to LIMs 106 via network114 in FIG. 1, persons skilled in the art will appreciate control module120 is coupled to communicate with LIMs 106 via network 114 in each ofthe other figures as well. For example, each of LIMs 106 may beindividually addressable via network communications from control module120, which may select the appropriate LIMs to command based oninformation stored about the LIMs in data store 116. Moreover, thecommunications between LIMs 106, network 114 and control module 120 maybe accomplished in a wide variety of ways, including any wired orwireless connections such as via Ethernet (typically a directconnection), Bluetooth and/or cellular service (typically accomplishedvia wireless connections). Alternately, LIMs 106 may be coupled tocontrol module 120 via a direct, hard-wired connection.

Each of LIMs 106 operates in essentially the same manner regardless ofwhich direction the electromagnetic force may be applied. When controlmodule 120 sends a signal to a given LIM 106, a current is generated incoils or wires within LIM 106. The signal may be a simple AC signal, orit may be a more complex signal, such as a PWM signal, depending on theneed. The generated current causes a magnetic field “B” to be generatedperpendicular to receiving surface 102 (see FIG. 4). The generatedmagnetic field B then induces a current “I” in conductive element 130that is a part of receptacle 110. Current I is generated parallel tosurface 102, but in a direction that is perpendicular to the intendedaxis of travel of receptacles 110. The interaction between the generatedmagnetic field and the induced current, causes a force “F” to be appliedto receptacle 110 that causes receptacle 110 to move in a direction “X.”The applied force needs to be, at a minimum, greater than the surfacefriction between receiving surface 102 and receptacles 110 in order tomove the receptacles. Accordingly, during system operations, based onall of the known information, such as the contents of each receptacle110, the weight of the receptacle and contents, etc., control module 120can generate varying signals to be applied to each individual LIM todynamically control the movement, speed, stopping and starting of theLIMs as they travel throughout the materials handling system.

Persons skilled in the art will appreciate that, in accordance with thedisclosures herein, the distance between receptacles 110 and LIMs 106,which is indicated by reference “A” in FIG. 4, is exaggerated forillustrative purposes only, and that the actual distance between LIMs106 and receptacles 110 may be as small as a few millimeters in order tomaximize the interaction between the generated field and the inducedcurrent. Persons skilled in the art will also appreciate that theinteraction between LIMs 106 and conductive portion 130 may result inreceptacles 110 being levitated at least a small portion above receivingsurface 102. The levitation may vary based on a number of factors, suchas, for example, the number and weights of items located within a givenreceptacle 110. Moreover, even if receptacle 110 is not actuallylevitated, it may be advantageous to apply the levitating force toreduce the surface friction between receiving surface 102 andreceptacles 110, which may reduce the energy needed to move receptacles110 throughout system 100.

Portable receptacles 110, with the conductive material incorporatedtherein, operate as what is traditionally one half of a standard linearinduction motor (that portion is sometimes referred to as a carrier orforcer). The other half of the linear induction motor, which isindicated throughout the disclosure as LIMs 106, may include a series ofmagnets installed in alternating polarity (that portion is sometimesreferred to as the magnetic rail or driver). The inclusion of conductiveportion 130 within receptacles 110 results in receptacles 110 being apart of the induction motor itself. This provides improvements overconventional systems, such as the ability to energize only thoseportions of materials handling system 100 that are currently being used.For example, if system 100 were utilized to move a single receptacle 100to three workstations in sequence for adding items from each workstation, only the LIMs close to the current path of travel need beenergized (for example, if the current path of travel caused receptacle110 to travel over 10 LIMs 106, only the 2 or 3 LIMs closest to theactual, current location of receptacle 110 need be energized at anypoint in time). This may result in significant energy savings, as wellas a significant reduction in moving parts that may require maintenance,create audible noise and generate dirt or dust within system 100.

FIGS. 5A-5D show schematic side views of some alternate ways to mountLIMs 106 to surface 102 in accordance with embodiments of the presentdisclosure. In FIG. 5A, for example, LIM 106 is mounted directly to theunderside portion of receiving surface 102. This implementation mayprovide LIMs 106 in close proximity to portable receptacles 110 as theypass by, but maintenance and repair may become difficult in view of thefact that LIMs 106 are essentially fixed in place. FIG. 5B, on the otherhand, shows a pair of guide rails 107 that are mounted to the undersideof receiving surface 102. In this example, LIMs 106 can be insertedbetween rails 107, which apply pressure to LIM 106 to keep it in place.This technique can simplify maintenance and repair, but installation maybe time consuming as each LIM 106 would need to be installedindividually. FIG. 5C shows an installation where a pair of small,U-shaped components or brackets are mounted to the underside ofreceiving surface 102 in order to retain LIMs 106 when they areinstalled therein. The installation shown in FIG. 5C provides similaradvantages to the installation shown in FIG. 5B, however, it requiresless material and provides access to more sides of LIMs 106. FIG. 5Dshows yet another potential installation of LIMs 106. As shown in FIG.5D, LIMs 106 may be incorporated at least partially or completely withinreceiving surface 102 itself, in which case receiving surface 102 mayneed to be implemented as something more than a single sheet of metal.Such an implementation could simplify construction and/or expansion ofmaterials handling system 100, because LIMs 106 would already be locatedin place once receiving surface 102 had been installed. Alternatively,LIMs 106 may be mounted to an upper side of receiving surface 102 usingany of the additional rails, components or brackets described above withreference to FIGS. 5A-5D, and the LIMs 106 may be at least partially orcompletely embedded within receiving surface 102 (e.g., partiallyembedded within channels or pockets from the upper side of receivingsurface 102). In the case where LIMs 106 may at least partially protrudeabove the upper side of receiving surface 102, the lower surface ofreceptacles 110 may be configured to provide any additional requiredclearance (e.g., as shown in FIGS. 10J and 10K) to travel unimpeded overLIMs 106. Installation, maintenance and repair of LIMs 106 may befacilitated by mounting LIMs 106 to the upper side of receiving surface102, depending on the accessibility and installed height of receivingsurface 102 within system 100.

FIG. 6 shows a schematic three dimensional perspective view of materialshandling system 100, which includes receiving surface 102, guides 104,and LIMs 106. Portable receptacles 110 may move along receiving surface102 in the “X” direction as a result of a force acting on portablereceptacles 110. For example, a magnetic field B generated by LIM 106perpendicular to the X direction of travel (as shown in FIG. 4), maygenerate a current I within conductive element 130 on a lower portion ofportable receptacles 110, which, based on Ampere's Law, creates a forceF on the conductive element 130 that causes receptacle 110 to move inthe X direction. That force operates to move receptacle 110, forexample, from LIM 106C to LIM 106B, which then creates its own force Fthat continues the movement of receptacle 110. Once receptacle 110 hasmoved within the magnetic field B generated by LIM 106A, a current isagain generated in conductive portion 130 of receptacle 110, whichcreates a force F that continues the movement of receptacle 110 alongdirection X.

FIG. 7 shows a schematic three dimensional perspective view of materialshandling system 100 in which embodiments are disclosed where a generatedforce F applied to a single receptacle causes multiple receptacles 110to move along the X direction on receiving surface 102. For purposes ofillustration, LIMs 106 in FIG. 7 are labeled individually as LIMs 106Aand 106C, and receptacles 110 are labeled individually as receptacles110A, 110B, and 100C. As receptacle 110C moves in proximity to LIM 106C,LIM 106C may be activated by control module 120 described herein suchthat a magnetic field B is generated by LIM 106C in substantially thesame direction as previously described (see FIG. 4), which generates acurrent I in conductive portion 130 of receptacle 110C that causes aforce F to be generated at receptacle 110C, moving receptacle 110C pastLIM 106C. In this instance, the signals generated by control module 120should create enough force such that all of receptacles 110A, 110B and110C are driven in the X direction from a single applied force toreceptacle 110C. Alternatively, receptacles 110A, 110B, and 110C mayhave enough kinetic energy when approaching LIM 106C such that they maycontinue to move along the X direction all the way to LIM 106A withoutLIM 106C applying any additional force on receptacle 110 (this depends,for example, on many factors such as the location and spacing of LIMs106 from each other and/or the configuration or elevations of receivingsurface 102). Persons of ordinary skill in the art will recognize thatLIM 106C, in one exemplary embodiment, may generate a magnetic field Bin a direction different than the magnetic field generated by LIM 106A,which may modify the direction and/or speed of movement of the portablereceptacle 110.

Once receptacle 110 begins to move across LIM 106C, the counterelectromotive force, or back EMF, generated by receptacle 110 can beutilized to identify the location of receptacle 110 to control module120 (which, in turn, may provide that information to data store 116 orstorage 126). Back EMF, for example, occurs due to the electromagneticfield induced by conductive element 130 passing by LIM 106C. The backEMF is measurable at any point along receiving surface 102, and inparticular, at each of LIMs 106. The back EMF may, in some embodiments,be used as a means to detect when each receptacle 110 reaches a specificLIM 106. As another example, the back EMF may be used to determine thecurrent approximate weight of each portable receptacle 110 based on thestrength of the magnetic field generated by the corresponding LIM 106,and the inherent impedance of the LIM 106. However, in some embodiments,one or more additional sensors (for example, see FIG. 1, and asdescribed below with respect to FIG. 10E) may be included withinmaterials handling system 100 that can be coupled to control module 120via network 114 to detect when a specific receptacle reaches a specificposition within system 100, as well as, or in addition to, the weight orcontent type of one or more items within a given receptacle 110.

Control module 120 may further cause LIM 106C to generate a magneticfield B that provides a force F that acts on receptacle 110 that maycause receptacle 110 to continue moving along the X direction toward asubsequent LIM 106. This process may be repeated any number of times tomove receptacle 110 along receiving surface 102. Furthermore, asillustrated in FIG. 6, each individual receptacle 110 can beindividually manipulated through handling system 100. Persons of skillin the art will appreciate that receptacles 110 may be moved along the Xdirection in different manners than described above. For example,receptacles 110 may be moved by LIM 106C directly to LIM 106A, such thatLIM 106B is not activated at all. In that instance, for example, LIM106B may be utilized as a back-up LIM providing redundancy in the eventthat LIM 106A or LIM 106C fails to operate in the intended manner.Alternatively, receiving surface 102 may include more than one axis oftravel and LIM 106B might be utilized to change the direction ofreceptacle 110 from traveling along the X direction to another direction(see, for example, FIG. 8 below).

FIG. 8 shows a schematic top view of a materials handling system 200that may include receiving surface 102 (which, as described above, mayinclude one or more low-friction surfaces), LIMs 106 aligned alongmultiple directions or axes W, X, Y and Z, and direction switches 138that may be utilized to change the direction of a receptacle 110,initially traveling along one direction, to move along another differentdirection, such as when a receptacle is traveling in the X direction andis moved to one of direction W, direction Y or direction Z. For purposesof illustration, switches 138 are labeled as switch 138A, switch 138Band switch 138C, which are operable to cause the direction of travel ofreceptacles 110 to change. In some embodiments, switches 138 may beimplemented as additional LIMs that change the direction of a portablereceptacle through the use of applied magnetic forces. In otherembodiments, switches 138 may be implemented as mechanical arms that canbe controlled or actuated by signals from control module 120. Moreover,not all of the LIMs 106 shown in FIG. 8 may be required for normaloperations. For example, the LIMs along the X direction are labeledalternately as LIM 106A and LIM 106B such that receptacles 110 may bedriven by LIMs 106A, while LIMs 106B are utilized as redundant backupLIMs in the event of failure of one or more of LIMs 106A. Each of LIMs106, 106A and 106B is coupled to control module 120, such that controlmodule 120 can provide operational commands to each of LIMs 106 insystem 200.

Materials handling system 200, like materials handling system 100described above, is in most instances just a portion of a much largerinventory management system that can be utilized to collect andtransport individual items. Accordingly, persons skilled in the art willappreciate that a complete materials handling system might include oneor more instances of systems 100 and 200 (or other configurations thatare not shown). Materials handling system 200 can direct portablereceptacles along the X direction, or from the X direction to the Wdirection, the Y direction or the Z direction, depending on the desireddestination. For example, receptacle 110 (shown in FIG. 8) can be movingalong the X direction from a given LIM 106 to another LIM 106. Controlmodule 120, in one embodiment, may send a generated signal to LIM 138Athat causes LIM 138A to generate a magnetic field B that provides aforce F that can act on conductive portion 130 of receptacle 110 tocause receptacle 110 to change direction from the X direction in whichthe receptacle is traveling to the W direction, where it may be pickedup by one or more of LIMs 106 that are located along the W direction.Similarly, LIM 138B may be utilized to generate a magnetic field B suchthat a force F acts on receptacle 110 causing receptacle 110 to changedirection from the X direction to the Z direction; LIM 138C cansimilarly cause receptacle 110 to change direction from the X directionto the Y direction; and LIM 138D can cause receptacle 110 to changedirection from the X direction to the Q direction.

While FIG. 8 shows a more complex implementation of a materials handlingsystem 200, it should be noted that such systems, utilizing theprinciples described herein, can be configured such that receptacles 110may enter and exit the system from a variety of locations. For example,a path along the Q direction may be utilized such that receptacles 110traveling along the Q direction travel directly across surface 102through the area by which other receptacles are traveling in the Xdirection. System 200 may be capable of implementing this featurebecause the system is inherently deterministic, such that the locationof virtually every receptacle 110 is known to control module 120.Accordingly, control module 120 could stop a given receptacle 110traveling along direction Q prior to the intersection with direction Xwhile waiting for traffic of receptacles traveling in the X direction toclear. Once an opening is identified, control module 120 could send theappropriate signal to LIMs 106 along direction Q to cause the stoppedreceptacle 110 to again move and now travel across the portion of thesystem normally traveled by receptacles 110 moving in the X direction.

FIG. 8 also shows an illustrative work station 160, which is intended asan example of the countless work stations that exist within materialshandling systems 100 and 200. Work stations 160 may include, forexample, work stations where empty receptacles are loaded onto orremoved from receiving surface 102, work stations where items are loadedinto or removed from receptacles 110 for storage in system 100, workstations where items are removed from inventory and loaded into orremoved from receptacles 110 for shipment to consumers, work stationswhere shipping materials are stored for preparation of shipments, workstations where items and/or receptacles 110 are subject to qualitychecks or maintenance, etc. Work stations 160 may be utilized, forexample, as follows. A given portable receptacle 110 enters the portionof system 200 shown at location “S” traveling along direction X. Switch138A (e.g., mechanical switch or LIM switch) is activated by controlmodule 120 which causes given receptacle 110 to be redirected fromtraveling in direction X to travel in direction W. When the receptaclearrives in the vicinity of LIM 106S, control module 120 issues a stopsignal to LIM 106S that causes the receptacle to stop in front of workstation 160 (LIMs 106 may be implemented, for example, such that anapplied magnetic field can be used to stop a receptacle 110 or move itforward or backward). At work station 160, for example, one or moreconsumer-selected items may be loaded into receptacle 110, or any otherprocessing may be performed with respect to items or the receptacle 110.This can be accomplished through a human interface, whereby anindividual places the item(s) in receptacle 110 and indicates to controlmodule 120, e.g., via user device 118, that the task is complete; or viaa robotic interface, in which case control module 120 would receive asignal from the robotic interface when loading was complete. Onceloading was complete, control module can provide an activation signal toLIM 106S that would cause the receptacle to again begin traveling alongdirection W to its next destination (which may, for example, be adifferent work station 160). Eventually, for example, that samereceptacle might return to traveling along direction X until the orderpreparation is complete and the order is sent off for shipping.

FIG. 9 shows a schematic side view of a materials handling system 300which is similar to previously described systems 100 and 200, exceptthat system 300 includes portions of the receiving surface 102 havingvarious elevations, e.g., a portion that goes up an incline U and aportion that goes down a decline D. System 300 includes a receivingsurface 102 within which LIMs 106 are mounted (in the manner previouslyshown and described with respect to FIG. 5D). Receptacles 110 move alongdirection X, propelled by electromagnetic force from LIMs 106. In thiscase, the spacing between LIMs 106 varies depending on where LIMs arelocated. For example, LIMs 106 that are located on the incline portion Uof the system 300 are labeled as LIMs 106H, and may be spaced closertogether to insure that control is maintained over receptacle 110 (butsuch close spacing is not required). Similarly, LIMs 106V are located onthe decline portion D of the system 300 with closer spacing to againmaintain control of receptacle 110 as it travels along direction X(similarly, such closer spacing may not be required).

As portable receptacles 110 move up incline U and down incline D,control module 120 may vary the signals applied to LIMs 106H and 106V toaccount for the variations in speed caused by the change in varyingelevation and gravitational forces. Moreover, because feedback oftraveling speeds can be provided to control module 120 in an essentiallyinstantaneous manner through the use of back EMF, control module 120 cangenerate varying control signals such that the speed of receptacles 110is maintained in a relatively constant manner (if that is the desiredresult).

FIG. 10A shows a schematic three dimensional perspective view of arepresentative portable receptacle 110, including side walls or portions110W, 110X, 110Y, and 110Z, a base portion 110V which has conductiveelement 130 attached to or integrated therein (for example, in FIG. 10A,conductive element 130 is shown to be covering base portion 110V). Theconductive element may, in some embodiments, correspond to a strip orpiece of copper, iron, silver, aluminum, or any other conductivematerial, or any combination thereof. Or the conductive element may beformed from material that is doped with conductive particles (e.g.,copper, iron, silver, etc.) into the non-conductive materials used toform the base portion or side walls or portions of the receptacle.Further, the conductive element may be placed on any surface of baseportion 110V, or at least partially or completely embedded within baseportion 110V, or the conductive element may be placed in any surface ofreceptacle 110 (for example, the left and/or right side walls ofreceptacles 110 may include a conductive element in which case LIMs 106could be mounted on stand-alone poles above and/or along the sides ofsurface 102 such that the conductive elements pass by proximate to theLIMs 106). It can be beneficial for portable receptacle to be aslight-weight as possible, as this will reduce the energy required tomove receptacles throughout the materials handling system. In order forreceptacles 110 to be able to interact with LIMs 106, at least a portionof receptacle 110 needs to be conductive. Accordingly, the receptacle110 shown in FIG. 10A includes non-conductive side walls or portions110W, 110X, 110Y and 110Z, while base portion 110V (which is underneathconductive element 130 in FIG. 10A) of receptacle 110 includesconductive element or insert 130 that can interact with LIMs 106. Whilereceptacle 110 shown in FIG. 10A is rectangular in shape, one ofordinary skill in the art will appreciate that a receptacle may haveother shapes, such as the round shapes shown in FIG. 11, other polygonalshapes or any other shapes configured to receive items therein.

The actual implementation of inclusion of a conductive portion intoreceptacles 110 can vary greatly within the spirit of the disclosure.For example, FIGS. 10B-10F show various illustrative schematic top viewsof alternate configurations of conductive element 130 within the baseportion of portable receptacle 110. Persons of ordinary skill in the artwill recognize that these are merely exemplary illustrations and thatthere are a multitude of different configurations to which the teachingsof the disclosure herein can be applied. For example, conductiveelements 130 may themselves be of any suitable size and/or shape,provided that there is enough conductive material to interact with themagnetic field B generated by LIMs 106. Furthermore, as mentioned above,the composition of conductive elements 130 may vary from a singleconductive material, to a compound of multiple conductive materials, tomixtures of non-conductive and conductive materials. For example, theconductive materials may include an array or grid of coils that arealigned such that an applied magnetic field would cause receptacle 110to move at a right angle down a different path than the path on which itwould otherwise travel. In that case, the change in direction may beless than ninety degrees due to the forward momentum that would alsoneed to be overcome when the field was applied.

In FIG. 10B, conductive element 130A is located in base portion 110V ofreceptacle 110 such that it can pass directly over any one of LIMs 106which are aligned along the intended path of travel of receptacles 110.In general, the size and orientation of conductive element 130 can beconfigured such that any of LIMs 106 can affect the trajectory and speedof receptacle 110, as described above. Although conductive element orinsert 130A is located at a first position along base portion 110V, insome embodiments, conductive element 130A may be positioned along anyother position along base portion 110V, such as proximate side walls orportions 110W, 110X, 110Y, or 110Z, and/or in a center of base portion110V.

FIG. 10C shows an alternate arrangement in which conductive strips ofmaterial 130B are embedded within base portion 110V. For example,conductive strips 130B may form a criss-cross pattern along the baseportion of receptacle 110, a checker board pattern, any other pattern,or any combination thereof (only a stripe pattern is shown). In someembodiments, conductive strips 130B may be on an outer surface of baseportion 110V, however, at least a portion of conductive strips 130B maybe embedded within a non-conductive material forming base portion 110V.

FIG. 10D shows another alternate configuration of conductive elements orinserts 130 applied to receptacle 110, in which two conductive elements130C and 130D are applied to or within base portion 110V. For example,conductive elements 130C and 130D may be attached to base portion 110V,but located close to either side wall or portion (e.g., 110W & 110Y or110X & 110Y) of base portion 110V. In some embodiments, conductiveelements 130C and 130D can be embedded within base portion 110V, whichmay be formed of a non-conductive material (e.g., similar to thenon-conductive material used to form side walls or portions 110W-Z).

In other configurations, conductive elements 130C and 130D can beoriented such that additional control of receptacle 110 may beaccomplished by utilizing LIMs 106 configured to be aligned withelements 130C and 130D. For example, receiving surface 102 may include afirst LIM oriented in a first direction and a second LIM oriented in asecond direction. When portable receptacle passes across the first LIM,conductive element 130C may interact with the first LIM such thatportable receptacle 110 moves in a first direction. When portablereceptacle passes across the second LIM, however, conductive element130D may interact with the second LIM, thereby causing portablereceptacle 110 to move in a second direction. In this particularscenario, a single portable receptacle 110 is capable of moving in anynumber of directions based on the orientation of the LIMs located onreceiving surface 102 of materials handling system 100.

FIG. 10E shows yet another configuration of base portion 110V. In thiscase, a conductive element 130E is applied to, or embedded in, baseportion 110V, as well as an additional item, such as an identifier, tagor other sensed element 140. Sensed element 140 may, in someembodiments, be used to monitor the location of receptacle 110 as ittravels about materials handling system 100, 200 and/or 300. Sensedelement 140 may be any type of identifier or tag including, but notlimited to, a Radio Frequency Identification (“RFID”) tag, a bar code, aQR code, an alphanumeric identifier, or other identifier. Sensor 112 ofFIG. 1, for example, may, in one embodiment, read, scan, image orotherwise identify sensed element 140 in order to detect portablereceptacle 110 and/or one or more items stored therein. In response todetecting sensed element 140, sensor 112 may send a signal to sensormodule 132 of control module 120 to cross check whether or not portablereceptacle 110 is moving in a correct direction (e.g., to a correct endpoint) and/or if portable receptacle includes the correct items therein,for example, by reference to information stored in data store 116 orstorage 126.

FIG. 10F, on the other hand, shows a configuration in which threedifferent conductive elements 130F, 130G, and 130M are included withinbase portion 110V in order to provide more precise control of receptacle110. For example, conductive portion 130F may be utilized to movereceptacle 110 along a first direction, conductive portion 130G may beutilized to move receptacle 110 along a second direction, and conductiveportion 130M may be utilized in changing direction of receptacle 110.

FIG. 10G shows a schematic cross-sectional view of receptacle 110. Forexample, FIG. 10G shows that conductive material 130N has beenimpregnated into base portion 110V, e.g., by doping the material of thebase portion with conductive material during manufacturing of receptacle110 (in FIG. 10G, base portion 110V and conductive element 130N are, inessence, one in the same and only reference numeral 130N is shown). Inthat instance, the use of conductive material might not be apparent toan observer or an employee handling the receptacle 110. Base portion110V, in this particular scenario, may be formed of a non-conductivematerial, such as plastic or cardboard, that has conductive elementsimpregnated therein such that base portion 110V retains the quality andappearance of a non-conductive material, similar to side walls orportions 110W-Z, but includes the appropriate conductive features forinteracting with various LIMs 106.

FIGS. 10H-10K show alternate physical configurations of receptacle 110which are intended to provide a reduced surface area that would be incontact with surface 102, to reduce the surface friction between thosesurfaces. FIG. 10H, for example, shows a schematic top view ofreceptacle 110 including conductive element 130H. FIG. 10I shows aschematic side view of the receptacle shown in FIG. 10H, in which only asmall portion of the outer edge of receptacle 110 extends fully to alower surface that contacts surface 102. More particularly, only theouter rim 110R of the base portion extends fully to the bottom ofreceptacle 110, while conductive element 130H is raised slightly so thatit is not in contact with surface 102 while receptacle 110 is beingtransported within materials handling system 100, 200, and/or 300.Similarly, FIGS. 10J and 10K show another configuration for base portion110V in which only legs 110L of base portion 110V extend down ontosurface 102 while receptacle 110 is being transported within system 100,200, and/or 300, further reducing the surface friction between surface102 and receptacle 110. In this configuration, only a very small portionof receptacle 110 is ever in physical contact with receiving surface102; accordingly, the surface friction that needs to be overcome forinducing movement of an empty receptacle may be significantly reduced ascompared to a receptacle with a continuous planar bottom surface.Moreover, the conductive element 130J is shown as a generalrepresentation in FIG. 10K and can, for example, be configured in atleast any manner previously described with respect to FIGS. 10A-10G. Italso may be beneficial to utilize wheels or rollers in place of legs110L to further reduce the surface friction between surface 102 andreceptacle 110. In such an implementation, surface 102 and receptacle110 may be designed such that the wheels or rollers 110L could fitwithin a portion of surface 102 to help guide receptacle 110 to theproper location.

FIGS. 11A and 11B show three dimensional schematic views of receptacle170, which is substantially similar to receptacle 100, except that it isshaped in a cylindrical manner instead of a rectangular shape. Moreover,persons of ordinary skill in the art will appreciate that a variety ofother shapes, such as other polygons or any other shapes configured toreceive items therein, may also be utilized as portable receptacles inaccordance with the present disclosure. In particular, FIG. 11A shows aconfiguration of receptacle 170 in which conductive element 130K islocated within base portion 110V of receptacle 170 such that it may bein contact with receiving surface 102 while receptacle 170 moves alongmaterial handling system 100, 200, and/or 300 (in FIG. 11A, base portion110V and conductive element 130K are shown in the same manner as baseportion 110V and conductive element 130J described above). FIG. 11B, onthe other hand, shows an alternate version of receptacle 170 in whichconductive element 130L is raised above the bottom of base portion 110R,similar to that shown in FIGS. 10H and 10I, to reduce surface friction.

FIG. 12 shows a flow diagram of a method 900 for fulfilling an orderutilizing a portable receptacle that is at least partially conductivewithin a materials handling system in accordance with the disclosureherein. In this regard, it may be helpful to also review FIG. 1 and theaccompanying description above, particularly with regard to controlmodule 120 and the modules contained there. The method starts at step902. In step 904, an instruction is given, for example by control module120, to direct that a receptacle be placed at a given location withinthe materials handling system (that instruction may be carried out by anemployee or by an automated part of the system that could place areceptacle 110 on to an entry point on receiving surface 102). In step906, an analysis is performed to determine the path the placedreceptacle needs to travel to complete the order for that receptacle,including determining which LIMs will be required to propel thereceptacle around the materials handling system. This analysis may beperformed, for example, by control module 120.

In step 908, a query is made to determine whether the order is completefor the corresponding receptacle (this query could be made, for example,by processor(s) 122 within control module 120 of a user device 118 whichis being operated by an employee; alternatively, the status of a givenorder being processed may be stored in memory 124 and accessed byprocessor(s) 122 in order to complete the inquiry). If the order is notcomplete, in a step 910, the appropriate LIM is sent a signal (by signalgenerating module 134, which may be in response to an activation signalfrom processor(s) 122), which activates the LIM to generate a magneticfield B, which induces a current I in the conductive portion of thereceptacle and creates a force F that moves the receptacle to the “nextlocation.” Next, in a step 912 another query is made to determinewhether the “next location” at which the receptacle arrived is aworkstation, other processing area or a final destination (this querycould be made by processor(s) 122, for example, by seeking the status ofone or more sensors 112 via sensor module 132). If the “next location”is not a work station, other processing area or the final destination,it is assumed that the receptacle is at an intermediate LIM and that thereceptacle needs to be again transported to the “next location,” socontrol returns to step 910.

Once a work station, other processing area or the final destination isreached and the query at step 912 is true, the task at the work station,other processing area or the final destination is performed in step 914.This task or function may include placing one or more items in thereceptacle (which may occur manually, through a robot or a combinationthereof). This task also may include placing packaging materials in thereceptacle, and/or it may include removing the contents of thereceptacle, placing the contents in a shipping container and thenplacing the packaged items back in the receptacle for transportation tothe shipping work station (there can be a variety of tasks performed atwork stations, other processing area or the final destination, only someof which have been described herein—persons skilled in the art willappreciate that the individual workstation and processing tasksdescribed are not intended to limit the disclosure or claims in anyway). Once the work station or processing task has been performed,control is returned to the query at step 908 where processor(s) 122 candetermine whether the order is complete. If it is not yet complete,control is returned to step 910 to start the process of moving thereceptacle to the next work station (in which case processor(s) 122would continue to send signals to signal generation module 134 to causemodule 134 to generate and send drive signals to specific LIMs 106),other processing area or the final destination as previously described.If the order is complete and the receptacle has arrived at the finaldestination, control stops in step 916.

FIG. 13 shows a flow diagram of a method 920 for controlling themovement of a portable receptacle that is at least partially conductivewithin a materials handling system in accordance with the disclosureherein. Method 920, which starts at step 922, may be carried out, forexample, by control module 120, which was described in detail above withrespect to FIG. 1 (as such, it may be helpful to refer back to thedescription of FIG. 1, and in particular, to the description set forthin connection with control module 120 and the modules contained there).In step 924, status information is received regarding an individualreceptacle from one or more sensors (this may include, for example,utilizing sensor module 132 to gather information from one or more ofsensors 112, and for sensor module 132 to send that gathered informationto processor(s) 122). This information can relate to any of a number ofdifferent things, such as the identification of the individualreceptacle, the location of the receptacle, the status of completion ofthe order intended for that receptacle, the current contents of thereceptacle, the overall weight of the receptacle with the contentstherein, etc. This information can be provided by one or more sensorswhich may include RFID readers, sensors to measure back EMF signals fromone or more of the LIMs, imaging sensors, scanners, or other sensordevices.

Once the information has been obtained, in a step 926, the individualreceptacle and corresponding information are matched together and thephysical receptacle and corresponding nearby LIM are identified andlocated within the materials handling system (this step can be carriedout, for example, by processor(s) 122, which may store such informationabout each active receptacle in memory 124 and/or storage 126, and whichcould then update the stored information based on the received statusinformation). Then, in a step 928, the “next location” to which theindividual receptacle is to travel is identified (this step could alsobe carried out by processor(s) 122). This “next location” may be a workstation, other processing area or the final destination or it may simplybe the next LIM in sequence on the way to a work station, otherprocessing area or the final destination in future steps.

In step 930, control module 120 determines the direction in which aforce should be applied by the LIM to the receptacle to propel it towardits “next location,” and in step 932 control module 120 determines theamount of force that should be applied by the LIM to the receptacle(this determination may take into account, for example, the weight ofthe receptacle, the weight of the contents and/or a desired distance tobe traveled). It should also be noted that the particular order of steps930 and 932 is not critical, and that they may be reversed or combinedinto a single step, as appropriate. Once the direction and size of theapplied force has been determined by control module 120 and thatinformation is sent to signal generation module 134, signal generationmodule 134, in step 934, generates an appropriate drive signal to beapplied to the corresponding LIM. In step 936, the generated signal istransmitted to the appropriate LIM by signal generation module 134 whichcauses that LIM to generate a magnetic field B that interacts with theconductive portion of the corresponding receptacle to induce a currentI, that in turn creates a force F that moves the receptacle to the “nextlocation.” The method stops in step 938 (or simply repeats until theoutstanding tasks for the receptacle are complete).

The various embodiments described herein may be implemented using avariety of means including, but not limited to, software, hardware,and/or a combination of software and hardware. Furthermore, the abovedescribed embodiments are presented for the purposes of illustration andare not to be construed as limitations.

What is claimed is:
 1. A materials handling system, comprising: a trackcomprising a receiving surface to move a receptacle along the track froma first position to a second position; a plurality of receptacles, eachreceptacle of the plurality of receptacles comprising a conductiveelement arranged proximate to the receiving surface of the track, theconductive element comprising at least a conductive material impregnatedinto a portion of each receptacle; a plurality of linear inductionmotors (“LIMs”) disposed along the track, each LIM of the plurality ofLIMs situated on the track in close proximity to the conductive elementof a receptacle passing thereby; and a control module that controlsforce produced by a LIM on the conductive element of the receptaclepassing thereby, wherein the control module is operable to control theforce produced by each LIM independently to propel receptaclesindependently of each other along the track.
 2. The materials handlingsystem of claim 1, wherein each receptacle of the plurality ofreceptacles is capable of receiving at least one item to be storedtherein as the receptacle is moved along the track from the firstposition to the second position.
 3. The materials handling system ofclaim 1, wherein the conductive element further comprises at least oneof: a conductive plate located on each receptacle.
 4. The materialshandling system of claim 1, wherein the control module is furtherconfigured to: control the force produced by the LIM on the conductiveelement of the receptacle passing thereby such that the receptacle movesalong the track from the first location to the second location.
 5. Thematerials handling system of claim 1, further comprising: at least onesensor for measuring a weight of each receptacle.
 6. A materialshandling system, comprising: a track for moving a receptacle along areceiving surface of the track, the track comprising a plurality oflinear induction motors (“LIMs”) disposed along at least a portion ofthe track; and a plurality of receptacles configured to receive at leastone item, wherein: each receptacle comprises a conductive elementoriented proximate the receiving surface when each receptacle ispositioned on the track, the conductive element comprising at least oneconductive material included within a non-conductive portion of eachreceptacle; and each of the plurality of LIMs are arranged along thetrack proximate the receiving surface in a configuration to propelreceptacles along the receiving surface between at least two positionson the track.
 7. The materials handling system of claim 6, wherein theplurality of LIMs are further arranged to control movement of any of theplurality of receptacles between any of the at least two positions. 8.The materials handling system of claim 7, wherein each LIM of theplurality of LIMs is configured to control a corresponding receptaclethat is passing by that LIM such that each receptacle of the pluralityof receptacles is individually controlled by a LIM of the plurality ofLIMs.
 9. The materials handling system of claim 6, further comprising: aplurality of sensors configured to monitor at least one of: a locationof the plurality of receptacles; or the at least one item received ineach of the plurality of receptacles.
 10. The materials handling systemof claim 6, wherein the plurality of LIMs comprise: a first group ofLIMs configured to move receptacles in a first direction along thetrack; and a second group of LIMs configured to move receptacles in asecond direction along the track.
 11. The materials handling system ofclaim 10, wherein at least one of the LIMs in the second group of LIMsis operable to cause electromagnetic force to be applied to receptaclespassing thereby to change a direction of movement of the receptaclesfrom the first direction to substantially the second direction.
 12. Amethod for controlling a materials handling system, the methodcomprising: instructing, by a control module, placement of a receptacleon a receiving surface of a track, the receiving surface of the trackcomprising a plurality of linear induction motors (“LIMs”), and thereceptacle being configured to receive at least one item and comprisinga conductive element that is positioned proximate to the receivingsurface, the conductive element comprising at least one conductivematerial included within a non-conductive portion of each receptacle;and instructing, by the control module, operation of at least some ofthe plurality of LIMs according to a sequence that causes the receptacleto move in a first direction along the receiving surface viaelectromagnetic coupling between each one of the at least some of theplurality of LIMs and the conductive element of the receptacle passingthereby.
 13. The method of claim 12, wherein instructing operation of atleast some of the plurality of LIMs further comprises: applying analternating current (“AC”) signal to a selected LIM of the plurality ofLIMs to generate a magnetic field configured to couple with thereceptacle passing thereby to induce a current in the conductiveelement.
 14. The method of claim 12, wherein the applied AC signal is apulse width modulated (“PWM”) signal.
 15. The method of claim 14,wherein applying the PWM signal causes eddy currents to be created inthe conductive element of the receptacle which interact with theelectromagnetic field to create a force that propels the receptacle tomove in the first direction.
 16. The method of claim 12, furthercomprising: sensing, by at least one sensor, at least one of: a locationof the receptacle within the materials handling system or the itemreceived in the receptacle.
 17. The method of claim 12, furthercomprising: diverting, by at least one of the plurality of LIMs, thereceptacle from the first direction to a second direction.
 18. Themethod of claim 17, wherein diverting comprises: applying a first pulsewidth modulated (“PWM”) signal to a selected LIM of the plurality ofLIMs to generate an electromagnetic field configured to couple with theconductive element of the receptacle to cause the receptacle passingthereby to move in the second direction.
 19. The method of claim 18,further comprising: applying a second pulse width modulated (“PWM”)signal to a selected LIM aligned along the second direction, wherein thesecond PWM signal generates an electromagnetic field configured tocouple with the conductive element of the receptacle to cause thereceptacle passing thereby to continue to move along the seconddirection.
 20. A receptacle, comprising: at least one side wallcomprising a non-conductive material; and a base, wherein: at least oneof the at least one side wall or the base comprises at least oneconductive element configured to interact with a linear induction motor(“LIM”) when the receptacle is proximate the LIM, the at least oneconductive element comprising at least one conductive material includedwithin a non-conductive portion of the base; and the at least one sidewall and the base of the receptacle are configured to receive at leastone item.
 21. The receptacle of claim 20, wherein the base furthercomprises the non-conductive material; and the at least one conductivematerial included within the non-conductive portion of the basecorresponds the at least one conductive material being impregnated intothe non-conductive material of the base.
 22. The receptacle of claim 20,wherein: the at least one side wall comprises first, second, third, andfourth side walls; the first and the second side walls are substantiallyparallel to one another and the third and fourth side walls aresubstantially parallel to one another such that the first and secondside walls are substantially perpendicular to the third and fourth sidewalls; and the base is substantially planar and oriented such that it issubstantially perpendicular to the first, second, third, and fourth sidewalls.
 23. The receptacle of claim 20, wherein: the base furthercomprises the non-conductive material; and the at least one conductiveelement further comprises a plurality of conductive strips interposedwithin the non-conductive material.
 24. The receptacle of claim 20,wherein: the conductive material comprises at least one of copper, iron,aluminum, or silver.
 25. The receptacle of claim 20, wherein the basefurther comprises an RFID tag configured to be read by an RFID reader totrack a position of the receptacle within a materials handling system.